I changed the question again to international law. In response to other counsel's comments, a child is not emancipated by being a full time student if the the custody obligation continues until the child is 21 in NY).

The issue would be governed by an international treaty: the "Convention on the Service Abroad of Judicial and Extrajudicial Documents in Civil or Commercial Matters of 1965", more commonly called the Hague Service Convention. See the wiki link below.

Basically, what you would have to do is get a certified copy of the NY Family Court Support Order (with a formal endorsement attached called an "apostle" from the NY Secretary of State, see the webpage, second link below.

Depending on the status of Argentina and Poland under the Hague Service Convention, you either serve papers on the country's designated representative (easy, fast), or you have to make a formal request through diplomatic channels (slow). You will probably have to retain counsel in Poland to chase your ex around with whatever enforcement procedures exist in Poland.

A daunting task, but not impossible. Good luck.

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p.s. You'd probably ALSO have to get a certified copy of the arrears statement from the State or County Support Collection Unit, assuming the support payments were collected by the SCU. If they were privately paid, you'll need some kind of affidavit and account statement (ledger) of the payments due and those paid. This document will also need an apostile.

There are number of issues: 1) whether your daughter is emancipated; 2) what court/state has jurisdiction over the emancipation issue. Emancipation laws vary (depending on what state you are in). Where is your daughter?

This answer is for informational purposes only and should not be construed as legal advice.

This is a family law question but also an international law question. Perhaps consider reposting under international law because of the question of how to internationally enforce (if possible) a child support order. Your daughter may still be eligible for child support if she is enrolled in college, but check with a local family attorney to make sure. Good luck.

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Done and answered. In NYS, full time attendance as a college student away from home is NOT considered emancipation. You are right this is an international law question, governed at the threshold by the Hague Service Convention. I didn't read the whole wiki article I linked with the signatories, but asked had better hope that both Argentina and Poland are signatories. It's not impossible otherwise, but slow. It isn't just third world countries or "rogue states" that aren't signatories. While the US is a signatory, its neighbor to the north, Canada, surprisingly isn't, especially since like the Scandanavian countries, Canadians seem to be active in the international realms of diplomacy and general do-goodism.